1. Field of the Invention
This invention relates to a hand-held calculator having a liquid crystal display supported on a transparent substrate so that portions of the LCD that are excited obstruct light passage while the reminder of the display is transparent to transmit light therethrough so as to afford projection of an enlarged image of the display onto a projection screen.
2. Description of the Prior Art
So far as is known, the only devices available for facilitating classroom instruction in the operation of a calculator are calculators having displays of large-emitting diodes, large Nixie tubes, or a simulated display having mechanical plates or bars which produce an output display that only remotely resembles the display actually seen on the conventional hand-held calculator. These devices in addition to producing a display unsuited for group viewing are of such high cost that their universal use is impractical.